Feanz spenglee



(No Model.)

1:". SPBNGLER.

LATOH BOLT. No. 390,409. Patented Oct. 2, 1888.

ATTORNEYS.

UNITED STATES ATNT @FFME.

FRANZ SPENGLER, OF BERLIN, GERMANY.

LATCH-BOLT.

SPECIFICATION forming part of Letters Patent No. 390,409, dated October 2, 1888.

Application filed December 19, 1887. Serial No.258fii8. (No model.)

To all whom it may concern.-

Be it known that I, FRANZ SPENoLEn, a subject of the King of Prussia, residing at Berlin, in the Kingdom of Prussia, German Empire, have invented new and useful Improvements in Latcli-Bolts, of which the following is a specification.

The invention relates to latclrbolts, the object of the invention being to provide a new and improved latch-bolt, in which the friction between the head of the bolt and the keeper on the door-casing is reduced to a minimum.

The invention consists in the peculiar construction of the bolt. as hereinafter described, and pointed out in the claim.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure 1 is a perspective view of the improvement. Fig. 2 isa front end elevation of the same. Fig. 3 is a sectional side elevation of part of the improvement on the line 00 a; of Fig. 2. Fig. 4 is a plan view of the same on the line y y of Fig. 3, and Fig. 5is an inverted plan View of the same on the linez 20f Fig. 3.

The latchbolis as heretofore constructed were formed at their projecting front ends or heads in the shape of a wedge, the entire inclined side of which came in contact with the keeper when closing the door, so that considerable friction was produced. With the improvement presently to be described this friction is reduced to a minimum, as the contact of the head of the bolt takes place only along a line instead of the entire inclined side when closing the door.

The latch-casing A is provided with the1ock ing-bolt B, against which presses a spring, (not shown,) so that the front end or head, C, of the bolt is held in an outermost positi0nthat is, it projects through the aperture D, formed in the front plate, E, of the casing A.

The headO of the bolt B, instead of being of the usual wedge shape,- is of an inclined pyramidal shape, as shown in the drawings, the base of the pyramid being the rear end of the head C, as is plainly shown in Fig. 1. The front edge, I) d, of the base of the pyramid is slightly inclined inward, and thepoint cof the pyramid is flush with the front plate, 19, when the bolt B isin its outermost positiomas shown in Fig. 1.

Now it will be seen that when the door is closed the contact of the head 0 of the bolt B with the keeper will only take place along the line of theedgeab of the pyramid, thereby reducing the friction to a minimum.

In order to supportthe bolt B when sliding inward on closing thedoor, Iprovidethe front plate, E, at its inside with an angle'iron, F, on which rests the bottom of the head 0 of the bolt when the latter is moved into its extreme innermost position, as shown. in dotted lines in Fig. 3.

The peculiar shape of the head (I of the bolt B maybe given to all kinds of bolts, whether straight or curved.

Having thus fully described my invention, I claim as new and desire to seen re by Letters Patent- A latchbolt of \vedgelike form and having its end beveled from edge to edge and from side to side, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FR A NZ SPEN G LEE.

Vitnesses: 7

GUSTAV H ULSMAN N,

B. Roi. 

